sync problem converting from mpg to avi

[dancray]

I have an mpg file I want to convert to smaller size avi, but when I set it up in virtual dub (using DIVX as compression) the result has an out of sync audio....actually it looks as though the video speeds up while the audio remains the same...very weird looking.

Does anyone have any suggestions on what may be happening; my settings are quite standard...I just choose the compression nd run "save as"...I even tried different compression but still ends up being out of sync.

thanks

ps...I have a pentium 3-500...fairly vanilla setup but lots of ram and hardrive space..